The fuel injector arrangement is configured to be inserted into an opening in a housing part to form a part of a fuel injection system. Said fuel injector arrangement or said fuel injection system may be used in an internal combustion engine, such as a diesel or gasoline engine, where said engine can be used in any vehicle or machinery; such as a car, motorcycle, truck, bus, construction equipment or stationary power units.
Fuel injectors are used to supply fuel into the cylinders of an internal combustion engine. According to one engine concept example, a fuel distribution channel (a fuel gallery or rail) is arranged crosswise through a housing for feeding fuel to a plurality of fuel injectors. Each fuel injector comprises an internal fuel channel arrangement extending between an opening into the fuel gallery and an opening in an injector tip forming a spray tip. In the fuel injector, the injection timing may be controlled mechanically and/or electrically/electronically: for example via a plunger by solenoid or piezoelectric actuator.
When fuel is injected into a combustion chamber of a cylinder, the combustion of said fuel results in a high gas pressure, which pressure exerts a force on the injector tip and all the way up to a contact area between the fuel injector and an injector sleeve and/or a housing part receiving the fuel injector. The contact area between the fuel injector and the injector sleeve/housing part is established and maintained by the clamping force of an injector yoke which counteracts the force caused by the gas pressure.
In the fields of diesel engines and direct injection type gasoline engines, a common rail fuel injection apparatus is known to be advantageous to pulverization of fuel spray and high pressure injection. In general, the common rail fuel injection apparatus has a common rail (accumulation chamber) for temporarily storing a fuel which has been pressurized by a high pressure pump. The fuel is injected into cylinders of an engine (or combustion chambers) in a predetermined amount at a time from an injector at a predetermined timing.
The injector generally has a plurality of injection openings (fuel spray outlets) at a lower end thereof which are opened and closed by a needle valve moving up and down inside an injectors body (nozzle body). A spring is also received in the injector body to bias the needle valve in a closing direction (downward direction). The needle valve is immersed in the high pressure fuel (i.e., the needle valve would float in a fuel pool if no downward force acts), and a downward spring force is applied to the needle valve so that a lower end of the needle valve is forced to contact a valve seat so as to close the injection openings of the injector. A downward fuel pressure applied on an upper end of the needle valve is controlled by a pressure control chamber (balance chamber). By appropriately leaking a high pressure fuel from the pressure control chamber, the pressure balance relative to the needle valve is lost so that the needle valve is caused to ascend and therefore the injection openings open.
The needle valve is received in a hole or bore formed in a nozzle body of the injector such that it can move up and down. The high pressure fuel fed from the common rail flows through a cylindrical clearance between the nozzle body hole and the needle valve and reaches the injection openings of the injector.
Accordingly, there is a need to better distribute fuel emitted from the fuel injector in order to obtain better efficiency.